Sliding-clutch-gear synchronizer



June 17, 1930. H. J. MURRAY SLIDING CLUTCH GEAR SYNGHRONIZER Filed June22, 1927 Y YT INVENTOR A TTORNEY Patented June 17, 1930 UNITED. STATESPATENT OFFICE HOWARD J. MURRAY, OF BROOKLYN, NEW YORK, ASSIGNOB TO B. M.COMPANY, INC., OF EAST PITTSBURGH, PENNSYLVANIA, A CORPORATION OFDELAWARE SLIDING- CLUTOH-GEAR SYNCHRONIZER Continuation of forfeitedapplication Serial No. 548,237, filed April 11, 192$. This applicationfiled June 22, 1927. Serial No. 200,746.

The invent-ion relates in eneral to a varia ble speed power transmissionmechanism of the gear shift t pc and in which the power driven gear andthe load carrying gear are coordinated through the interpos1tion of afriction clutch so that the gears will tend to assume a speed ofrotation approximately equal to each other before the gears are movedinto meshed position. This application constitutes a continuation offorfeited case Serial No. 548,237, filed April 11, 1923,

and allowed November 27, 1926. The in-- inoperative automatically justprior to the intermeshing of the gears in their direct driving relation.

This application is a companion to a copending application on a gearsynchronizing device filed under even date, Serial No. 548,235. In thecompanion application the specific form of friction clutch selected forillustration is of the internal band type with concentrically disposedclutching members and in which the clutching .movementtakes' placeradially of the axis of rotation of the intermeshing gears. The presentdisclosure features the use of a different form of friction clutch whichwill be referred to hereinafter as a clutch of the side face type due tothe fact that the clutch elements engage across a flat surface. In thiscase the movable element of the clutch is shiftable to and from itsclutching-engagement with one :of

sha which carries the same.

llhe present disclosure features the same advantages, such as simplicityin structural design, ease of control in operating the same,positiveness of actuation and ready substitution for the correspondinggear unit in transmission casings ofconventional construction as isfeatured in the companion application.

The present disclosure has for additional the ipower gears in adirection axially of the objects the providing of a form of frictionclutch which will provide for a maximum possible friction surface, whichwillprovide for a uniformity of brakingiefi'ect or efiiciencyindependent of wear of the parts which will prove a, form' of clutchwhich will eliminate any necessity for, adjustment of partsjto obtainuniform pressure.

Another object of the invention is to provide a form of clutchconnection which will be controlled in its intensity of engagementdirectly by the manual force of the operator in actuating the shiftinglevers. Still another object' is to provide a synchronizer of the typeoutlined in which the clutching action may be efiected by the initialmovement of the shifter levers and while the gears are running idle andin which the parts function in present sequence and with proper lapsedtime to effect the frictional connection between the synchronizer andits corelated gear before the power gears. are moved into intermeshingrelation irrespective as to how rapidly the operator may move thecontrol levers. r

A further object of the invention is to provide a simple means differingfrom the means shown in the copending application for insuring theproper meshing of the synchronizer gear with the corelated power gearwithout danger of stripping the teeth of either gears.

. Still another object of the invention is to' the invention will be inpart obvious from an inspection of the accompanying drawin and in partwill be more fully set forth in the following particular description andone form of mechanism embodying my. invention, and the invention alsoconsists in certain novel features of construction and combination ofclaimed.

lln the accompanying drawings 2 Figure l is a sectional view taken amally of the power shafts through a tr "12.1mm

parts hereinafter set forth and ice casing of conventional form,equipped with a preferred embodiment of the inventive features hereindisclosed, andalso constituting a modified form of the inventivefeatures disglosed in the above identified application; an

Figure 2 is an enlarged transverse sectional view taken on the line 2-2of Figure 1.

The gear unit 17 is provided with external teeth 19 hereinafter referredto as a driven gear and adapted when meshed with a gear 20 keyed to thecountershaft and hereinafter referred to specifically as a driving gear,to obtain second speed. Another gear 21 keyed to and slidably mounted onthe shaft portion 15 is designed in one shifted position to mesh with agear 22 on the countershaft to obtain first speed and in another shiftedposition to mesh with an intermediate gear 23 to obtain reversed speed.

In the following description particular reference will be made to thesynchronizing of gears 19 and 20 but it will be understood that theinvention with obvious mechanical changes can be adapted for use inother locations and as an illustration of one such use reference is madeto the first speed and reverse speed synchronizing arrangement shown atthe right side of Figure l. The shiftable gear unit 17 hereinillustrated is provided with a reduced sleeve extension 24 whichconstitutes a hub providing a circular bearing for the synchronizer. Anend plate 25 is secured to the end of the hub and is fastened thereto bymeans of long bolts 26. The end plate is provided on the side facing thehub with a radially extending bearing face 27 designed to constitute oneelement of a friction clutch of the side face type.

It will be noted in connection with the showing of gear 21 where theclutching is effected incidental to the shifting of the synchronizer inboth directions, that the gear itself is provided with a frictionclutching face 28 facing the clutching face 29 carried by the end plate30.

' The hub 24 provides a bearing for the synchronizer herein featured andthis synchronizer includes a synchronizer gear 31 mounted for rotarymovement on the hub and having a width slightly less than the length ofthe hub so that the gear is free to slide for a limited movement on thehub to and from its clutching engagement with the friction face 27. Thesynchronizer gear is a spur gear of ring form and is provided with aperipheral groove 32 into which extends a yoke arm 33 actuated by theusual control rod (not shown).

The portion of the shaft on which the shding gear moves is provided onone side thereof with a pair of recesses 34 and 35 opening one into theother longitudinally of the shaft,

with the recess 34 of greater depth than the recess 35 and with the endof the recess 34 rounding into the recess 35 to form a stop shoulder 36.The portion of the hub which slides over the recesses is cut-away asshown at 37 and a combined spring stop and friction brake 38 hereinafterreferred to as a locking cam is positioned in the recess. This lockingcam is a spring strip which extends circumferentially about the shaftportion 15 and is secured at one end to the shiftable gear 17 by screws39. The opposite, free end of the spring is provided with a,'roundedprojection 40 forming a cam stop held by the spring in bearingengagement with the shaft and projected into the recesses as the slidinggear is moved along the shaft. The portion of the stop 40 engaging therecesses is rounded as indicated at 41 so as to easily ride up theincline forming the shoulder 36 in its movement from one recess into theother. The locking cam is bent intermediate its length to form a squaredoffset portion 42 which provides a relatively extensive bearing surfacefor engaging the inner periphery 43 of the synchronizer gear as shownmore particularly in Figure 2. It will be understood that the parts areso proportioned that when the cam stop is in the deeper recess 34 thebearing portion 42 is fully removed from engagement with thesynchronizer gear and even when the cam stop is in the shallower recess35 the synchronizer gear will be free to rotate on the bearing hub. Whenthe cam stop is moved onto the unrecessed'portion of the shaft thesquared portion of the locking cam will be in tight binding engagementwith the synchronizer gear thus locking the same so as to rotate withthe shaft and with the sliding gear unit 17. While the cam stop ismoving along the recess 35 the synchronizer gear is idle so as not tohold the power gears at the instant they are moving into their meshingposition.

For the purpose of compensating for wear of the locking cam and theportion of the synchronizing gear against which it bears an adjustingdevice 43'- is provided. In the illustrated showing this is in the formof a small cam 44 adapted to be rotated by the turning of a rod 45 anddesigned to bear on the underside of the offset portion 44 and thusadjust the same relative to the inner periphery of the synchronizinggear.

In the device as thus far described, and also in the form of theinvention disclosed in the above identified application, it is intendedthat the synchronizer gear be at all times in such position relative tothe driving gear 20 that it can be moved into meshing relation withoutdanger of stripping the teeth of either gear. This may be effectedeither by bevelingthe edges of the teeth of the synchronizer and drivinggears so that they will easily mesh when brought into intermeshingposition, or by connecting the synchronizer gear to the driven shafteven when the synchronizer gear is in its idle osition as shown inFig. 1. It is suggested erein that the teeth of the synchronizer gear beextended to overlap the end plate so that the extended teeth portion 46will at all times be positively in mesh with the teeth at the gear 20.This hasthe additional advantage in that itwill eliminate changes in thedesign of. conventional forms of transmission due to varying dimensionsand positions of the power gears and, also in some forms oftransmissions, it will be possible to eliminate the necessity of thelocking cam herein disclosed.

In operation and assuming that. it is desired to move the gears 19 and20 from their unmeshed position shown in Figure 1 into their fullymeshed position as is usual in providing for second speed drives, thecon trol rod is moved to shift the yoke 33 to the right. It will benoted that when the gears I 19 and 20 are in their normal unmeshedposition, the cam stop is in the deeper recess and that the synchronizergear is in meshing engagement with the driving gear but is free torotate on the driven gear unit 17 The initial movement of the controllever shifts the synchronizer gear slightly and thus into clutchingengagement with the shiftable gear by bearing on the face 27. Thenormally free shiftable movement of the unit 17 is retardedby theengagement of the cam stop against the shoulder 36 at the end of thedeep recess. There is thus provided a friction drive between the drivingand driven power gears and this will cause the gears to be jerkedapproximately into the same speed during the instant of time that thecam stop is riding along up out of the deeper onto the shallower recess.With the continued movement of the shift lever the pressure actingthrough the synchronizing gear onto the shifting gear will overcome theholding resistance of the locking cam and thus'permit .the shifting gearunit to move its gear 19 into meshing engagement with the relativelyfixed gear 20. During this time the shifting yoke pressing on thesynchronizer gear in effecting its axial movement will have no effect onthe synchronizing gear in ,so far as its freedom of rotary movement isconcerned. As the sliding unit is moved along,

the gears are fully meshed and by this time the cam stophas ridden outof the shallower recess onto the unrecessed part of the shaft. This hasthe effect of causing 'the locking cam to bear against the synchronizergear and thus locks the same so as to rotate with the shaft. This takesplace before the syn-- chronizer gear leaves the driving gear20 andhence the synchronizer gear slides off and remains in proper angularrelation to mesh with the driving gear on the return movement.

By means of the form of clutch herein dis- I closed it is possible toobtain a directly applied manually controlled pressure between the facesof the clutch and any desired intensity. of frictional engagement may beattained by the sensitive control of the shift levers. It is appreciatedthat the utilizing of a. friction clutch of the side face type providesthe maximum possible friction surface shifting the gears. Thereisprovided a uniformity of braking effect or efliciency and this ismaintained independent of wear. and of course eliminates any necessityof adjustment to obtain uniform pressure as the parts wear away. Themaintaining of the'synchronizer gear permanently in mesh with thedriving gear eliminates any possibility of. stripping" of gears andconfines all strains to the friction clutch point of the drive.

Bymeans of the adjusting feature herein disclosed it is possible toobtain a nicet-y of adjustment between the locking cam and thesynchronize'r and in this way wearing of the parts is readilycompensated. While I have shown and described and have'pointed'out inthe annexed claims, certain novel features of my invention, it will beunderstood that various omissions, substitutions and changes in the formand details of the device illustrated and in its operation may be madeby those skilled in the invention.

Having thus described my invention, I claim 1. In a power transmission,the combination with a driving shaft and a driven shaft provided with arecess, a countershaft geared to thepower shaft and provided with apower gear fixed thereto, a gear unit slidably mounted'on the part ofthe driven shaft having the recess, said unit including a power gearadapted to mesh with the power gear on the countershaft and having a hubwith a radially extending bearing face projecting therefrom, asynchronizer gear mounted for rotary movement on the hub and providedwith a bearing face adapted to contact with the face on the hub to forma fri'ctionclutch, a spring controlled locking cam carried by thesliding gear unit and controlled by the movement of a-partof same intoand out of said .recess to interpose a. resistance to the free slidingmovement of the unit while functioning as part of the friction clutchand for locking the synchronizer gear to the driven shaft.

2. In a device of the class described, the combination of a shaft havinga pair of recesses disposed longitudinally, said recesses being ofdifierent depths and opening into each other, a sliding gear unit keyedto the shaft to rotate therewith, a synchronizer gear mounted on saidunit for rotary movement about the axis of said shaft, said synchronizergear and said unit provided-with means relatively movable axiallyandconstituting the coacting elements of a friction clutch, a springcontrolled locking cam including a cam stop adapted to ride into saidrecesses and controlled thereby when in the deeper of the two recessesto interpose a resistance to the free sliding movement of the unit whilefunctioning as the relatively fixed element of the friction clutch andwhen in the shallower of the recesses to permit the synchronizer to runidle and when on the unrecessed part of the shaft cause the locking camto bear on the synchronizer gear to cause the same to rotate with theunit and shaft and a control engaging the'synchronizer gear for shiftingthe same into its clutching position and acting therethrough forshifting the unit on the shaft and thus causing the looking cam tofunction.

3. In a gear transmission, the combination of a pair of powertransmitting shafts provided with gears relatively movable to and from ameshing position, one of said gears shiftable axially on its shaft, asynchronizer carried by said shiftable gear, a friction drive betweenthe synchronizer and said shiftable' gear to cause them to rotatetogether, locking means between the synchronizer'and shaft and a controlmovable in one direction for effecting in sequence a movement of thesynchronizer into clutching engagement with the sliding gear, a movementof the shiftable gear into mesh with the other gear and a movement ofthe locking means into operative position.

4. In a device of the class described, the combination of a shaftprovided with a recess, a power gear fixed thereto for rotary movementand slidable thereon axially across said recess, said gear constitutingan element of a friction clutch, a synchronizer gear mounted on thepower gear for rotary movement and free to move axially into engagementtherewith to constitute the coacting element of the 'friction clutch andmeans controlled by the position of the power gear relative to therecess for affecting a coupling of the synchronizer with the shaft sothat the synchronizer will rotate with the shaft and means for shiftingthe power gear together with the synchromzer along said shaft.

5. In a gear transmission, the combination of a. shaft, a power gearslidable thereon to and from a meshing position and constituting oneelement of a friction clutch, a synchronizer constituting the coactingelement of the clutch, a shift rod operatively connected to thesynchronizer to effect a clutching engagement between the synchronizerand the power gear on the initial part of its movement in shifting thepower gear into its meshing position and a locking cam controlled by theposition of the power gear on the shaft for connecting the synchronizerand shaft.

6. In a device of the class described, the, combination of a relativelyfixed gear, a relatively shiftablegear adapted to mesh with the fixedgear, a synchronizer gear, means for connecting the synchronizer gear tothe shiftable gear to effect a friction drive therebetween, and meansfor connecting the synchronizer gear to rotate with the 'fixed gear, anda shiftable control member bearing on the synchronizer gear to move thesame into bearing engagement with the shiftable gear.

7. In a device of the class described, the combination of a pair ofpower transmitting gears adapted to be moved to and from an intermeshingposition, one of said gears provided with a clutch surface, asynchronizing gear mounted for free rotary movement on said gear, andadapted tobe moved into meshing engagement with the other power gear,said synchronizing gear adapted to be moved axially into clutchingengagement with said clutch surface thereby to provide a friction drivebetween the synchronizing gear and the power gear on which it is mountedand manually actuated means directly engagingthe synchronizer gear forcontrolling the intermeshing relation of the power gears and forcontrolling the pressure between said clutch-surface andthesynchronizing gear.

8. In a device of the class described, the combination of a pair ofpower transmitting gears, one of which is slidable axially to and fromits meshing position with the other gear, a synchronizing gear mountedfor free rotary movement on the slidable gear and adapted to mesh withthe other power gear and otherwise normally independent of said othergear, said synchronizer gear adapted to coact with the gear on which itis mounted to form a friction clutch and manually actuated control meansoperatively connected directly to the synchronizer gear to effect insequence. themovement of the synchronizer gear axially into itsfrictional engagement with its associated power gear and then to slideboth the synchronizer gear and its associated power as a unit relativeto said other power ear. g 9. In a gear transmission, the combination ofa shaft, a'power gear slidable thereon to and "from a meshing positionand constituting one element of a friction clutch, means for restrainingthe freedom of axial movement of the slidable gear on its shaft, asynchronizer constituting the coacting element of the clutch, a shiftrod operatively connected to the synchronizer to effect a clutchingengagement between the synchronizer and the power gear on the initialpart of its movement in shifting the power gear into its meshingposition.

10. In a device of the class described, the combination of a pair ofpower transmitting gears relatively movable to and from an intermeshingposition, a synchronizer for causing the gears to approach the samespeed, said synchronizer including a synchronizer gear carried by one ofthe power gears and free to turn thereon, the synchronizer gear and thepower gear carrying the same having a limited freedom of relativemovement axially and coacting to provide a frictionclutch drive operablyindependent of the other gear.

11. In a device of the class described, the combination of a relativelyfixed gear, a relatively shiftable gear restrained in its axial movementadapted to be moved forcefully into mesh with the fixed gear, asynchronizergear normally disposed in mesh with the fixed gear and meansfor shifting the synchronizer gear axially of the shiftable gear andinto a frictional driving relation with the same while restrained fromaxial movement. a

12. In a device of the class desor' d, the combination of a power shaft,a p wer gear fixed thereto for rotary movement and adapted to be movedaxially along the same, means controlled by the position of the gear onthe shaft for resisting the axial movement of the gear, a synchronizergear mounted on the power gear for rotary movement and slidable axiallyto and from' a frictional engagement therewith and a control directlyengaging the synchronizer gear for shifting the same into frictionalclutching engagement with the power gear and for acting therethrough toshift the same along the shaft.

13. In a gear transmission, the combination of'a shaft, a power gearslidable thereon to and from a meshing position and constituting oneelement of a friction clutch, a

synchronizer constituting the coacting element of the clutch, a shiftrod operatively connected to the synchronizer to effect a clutchingengagement between the synchronizer and the power gear on the initialpart of its movement in shifting the power gear into its meshingposition and means for interposing a resistance to the free slidablemovement of the power gear on the shaft thereby to permit the frictionclutch to become effective.

14. In a device of the class described, the combination of a shaft, apair of power transmitting gear, one of which is shiftable on said shaftto and from an intermeshing engagement with the other gear, asynchronizer gear mounted for rotary. movement on engagement with theother gear, a synchro-' mzer gear provided on one side with a clutchface adapted to engage one side of the shiftable gear to provide afriction drive therebetween, and a control directly engaging thesynchronizer for effecting the clutching 0f the synchronizer gear withthe shiftable gear and for effecting a sequential meshing of the saidpair of gears.

16. In a device of the class described, the combination of a pair ofears, one of which is movable axially to and rom a meshing engagementwith the other gear, a synchronizer having a limited freedom of axialmovement into clutching engagement with one of the gears and adapted tomesh with the other gear whenmoved axially relative thereto and normallyotherwise independent of said other gear and resilient means tending torestrain thefreedom of axial movement of the gear which clutches withthe synchronizer.

17. In a device of the class described, the combination of a relativelyfixed gear, a shiftable gear adapted to mesh therewith, a synchronizergear mounted for rotary and longitudinal movement on the shiftable gear,said shiftable gear provided with an end piece adapted to coact with thesynchronizer gear to form a friction clutch drive between the same, saidsynchronizer gear having its teeth overlapping said end piece andadapted .tomesh with the fixed gear and means for shifting thesynchronizer into engagement with the end piece and to shift theshiftable tive to each other to and from a meshing position, asynchronizer carried by one of the gears and adapted to mesh with theother gear, a locking cam for connecting the synchronizer and itscarrying gear in inter-draw ing relation and means for adjusting saidlocking cam thereby to compensate for the wearing away of the same.

19. In a device of the class described, the

' combination of a shaft, a pair of power transmitting gears, one ofwhich is shiftable on 'said shaft to and from an intermeshing engagementwith the other gear, a synchronizer gear mounted for rotary movement onthe shiftable gear and adapted to mesh with'said other power gear, saidsynchronizer gear 45 into frictional clutching engagement with and saidshiftable gear provided with clutching means coacting to provide afriction drive between the same, and means engaging said synchronizergear to shift the same into and from its driving engagement with itscoacting gear.

20. In a device of the class described, the combination of a shaftprovided with a recess, of a gear unit slidable on the shaft, asynchronizer gear mounted on the unit for rotary movement, a locking camcontrolled by the position of the unit relative to the recess forsecuring the synchronizer gear to rotate with the unit and shaft andmanually actuated means for adjusting the locking cam.

21. In a device of the class described, the combination of a shaftprovided with a recess, of a gear unit slidable on the shaft, asynchronizer gear mounted on the unit for rotary movement, a locking camcontrolled by the position of the unit relative to the recess forsecuring the synchronizer gear to rotate with the unit and shaft andmeans associated with the locking cam for adjusting the same thereby tocompensate for wear of the cam and its associated parts.

22. In a gear synchronizing device, the combination with a pair of gearsadapted to be moved to and from a meshing position, of

' a synchronizer movable with one of the gears for causing the gears toapproach the same speed as they are moved towards their meshingposition, said synchronizer including a clutch member having a frictionsurface on one side face thereof adapted to engage one of the ears andmanually actuated means for contro ing the intensity of engagement ofthe clutch member with the said gear.

23. In a gear synchronizer, the combination of a gear provided with ahub extension constituting a shaft, a stop fixed to the shaft, asynchronizer gear mounted for rotary and slight axial movement on theshaft, manually controlled means for pressing the gear the stop, saidsynchronizer gear and said stop providing coacting clutch faces, one ofwhich is formed of a friction material.

Signed at New York, in the county of New York and State of New York this17th day of June A. D., 1927.

HOWARD J. MURRAY.

